Milking Speed (MSPD)

Available for Holsteins, Milking Speed estimates how fast a cow milks, expressed in pounds per minute.

Benefits of Trait

Introduced in August 2025, genetic and genomic evaluations for male and female Holsteins predict the average pounds of milk an animal’s offspring will give per minute in a conventional milking system. Evaluations are expressed on a phenotypic scale with a Holstein breed average of 7 pounds per minute.

Faster-milking cows can be selected for, allowing more cows to be milked through the parlor in the same period of time.
Slower-milking cows can be selected against, improving herd consistency and limiting disruptions to the milking routine.
Greater parlor throughput is a more efficient use of labor and facilities.

Learn more with frequently asked questions about this newest trait.

Milking Speed Trait

MSPD represents the average pounds of milk per minute expected of an animal’s offspring in a herd with average management conditions using a conventional milking system. Data used to support this trait is collected using sensor technology in parlors across the United States, providing an objective measurement tool for milking speed.

This trait is not to be confused with milking speed (MSP) produced for Brown Swiss and Milking Shorthorn, which is determined based on subjective producer reports collected during type classification.

Pounds of milk per minute, expressed on a phenotypic scale with the average set to 7 pounds per minute.

For example, daughters of a Holstein bull with a MSPD PTA of 8 pounds per minute are expected to milk faster than the average population. Conversely, daughters of a Holstein bull with a MSPD PTA of 6 pounds per minute are expected to milk more slowly.

Milking speed is calculated by dividing the total pounds of milk produced in an individual milking by the total milking duration in minutes. This provides a more accurate picture than simple milking duration, which does not account for the amount of milk the cow produced.

MSPD is currently available for Holsteins. As more data become available, evaluations will be provided for additional breeds.

MSPD will not be incorporated into the Lifetime Merit Indices at launch. It could be included in the future. MSPD is lowly correlated with Lifetime Net Merit $ (NM$), which suggests it is a trait not already captured in NM$ and could add significant economic value if incorporated.

It is suggested that producers continue to rely primarily on a composite economic index, with the specific choice dependent on the farm’s milk payment situation and management system. In the meantime, producers might consider avoiding bulls with extremely high or low predictions for MSPD.

MSPD heritability is estimated at 42%, making it a very heritable trait and a good selection option for dairy producers.

Young genomic bulls are expected to have reliabilities averaging 58%. Progeny-tested bulls are expected to have genomic reliabilities averaging 67%. As additional data are accumulated, reliabilities will increase.

The largest significant correlations of MSPD are with the PTAs for somatic cell score (SCS) at 0.43 and mastitis (MAST) at -0.28, while no phenotypic correlations are identified. This may be explained by the moderate to strong correlation between milking speed and milk yield and the well-known antagonistic correlation between milk yield and SCS.

No significant correlations are estimated between longevity or fertility traits.

MSPD evaluations are developed using milking time and yield information reported from in-line milk meters in traditional parlor systems that is then contributed to the National Cooperator Database by a dairy records processing center. This differs from MSP evaluations produced by CDCB for the Brown Swiss and Milking Shorthorn breeds and several international milking speed evaluations, which are calculated based on producer-reported perceptions of milking speed that are collected during type classification. By utilizing objective milking times and weights, the new MSPD trait eliminates the human factor needed for data collection in the other traits, creating a more accurate evaluation.

The research to develop MSPD analyzed a total of 131,015 lactation records from 121,662 cows and represented 11 different milking equipment manufacturers.

The standard deviation (variation) for MSPD in 0.3 pounds per minute. Because one and two standard deviations normally include 68% and 95% of observations, respectively, we assume about 68% of Holstein bulls will have a MSPD PTA between 6.7 pounds per minute and 7.3 pounds per minute and 95% of Holstein bulls will range from 6.4 pounds per minute to 7.6 pounds per minute.

A diagram of milking speed pta values

Description automatically generated

In evaluated Holstein bulls born since 2000, MSPD PTAs range from 5.9 pounds per minute to 8.2 pounds per minute with reliabilities of at least 90%.

Pre-release analysis indicated that the active A.I. Holstein sires in December 2024 (579 bulls) ranged from 6.2 pounds per minute to 8.1 pounds per minute, with the average at roughly 7.1 pounds per minute.

Future Development

As more data becomes available, MSPD evaluations can be provided for additional breeds. Since MSPD does not account for milking speed in automatic milking systems (AMS), data collection and evaluation potential for those systems will be investigated.

Related Publications

System and biological effects on quantitative milking speed phenotypes from inline milk meters. Miles et al, 2023

Genetic and genomic evaluations of quantitative milking speed phenotypes. Miles et al, 2024

Milking Speed: Genetic & Genomic Evaluations, Data Flow, & Next Steps Miles presentation at 2025 Western Dairy Management Conference

Milking Speed Fact Sheet

Information last updated July 17, 2025.